re PR c++/52748 ([C++11] N3276 changes to decltype)

re PR c++/52748 ([C++11] N3276 changes to decltype)

	N3276
	PR c++/52748
	* cp-tree.h (tsubst_flags): Add tf_decltype.
	* call.c (build_cxx_call): Don't build a temporary if it's set.
	(build_over_call): Make sure it's only passed to build_cxx_call.
	* parser.c (cp_parser_primary_expression): Add decltype_p parm.
	(cp_parser_unary_expression): Likewise.
	(cp_parser_cast_expression): Likewise.
	(cp_parser_binary_expression): Likewise.
	(cp_parser_assignment_expression): Likewise.
	(cp_parser_postfix_expression): Likewise.  Pass tf_decltype.
	(cp_parser_explicit_instantiation): Add decltype_p.  Force a
	temporary for a call on the LHS of a comma.
	(cp_parser_decltype): Pass true to decltype_p parms.
	* pt.c (tsubst) [DECLTYPE_TYPE]: Pass tf_decltype.
	(tsubst_copy_and_build): Pass tf_decltype down only for
	CALL_EXPR and the RHS of COMPOUND_EXPR.
	* tree.c (build_cplus_new): Call complete_type_or_maybe_complain.

From-SVN: r196736